Part 12470
Rev. 2 3/25/99
SELECTION OF OUTPUT TERMINAL
Three output terminals at various voltage and current ratings are provided to adapt the CB-832 to a
wide variety of test circuit impedances.
The Multi-Amp Model CB-832 circuit breaker test set has three current output terminals to provide a
wide range of current-voltage capabilities. The terminal with the lower current rating provides an
output with the highest voltage for testing devices of low current requirements but with high
impedance characteristics. This tap also has the highest output resolution capable of fine current
adjustments. The highest current rated output terminal provides high current availability for testing
devices of high current requirements of relatively low impedance. This tap offers the highest
resolution for voltage applications. Should the current required for the device to be tested exceed
the ability of the lowest tap or the impedance of the device to be tested require more voltage to
"push" the current than is available from the highest current tap, the medium range current tap can
be utilized to provide the current or voltage necessary to perform the desired test. Selection of the
output terminal depends entirely on the characteristics of the device to be tested, therefore, proper
selection will require some experimentation and will be easier as familiarity increases.
NOTE: There is no relationship between the ammeter ranges and the ratings of the output
terminal. All ammeter ranges can be used in conjunction with any of the output
terminals.
SELECTION OF OUTPUT LEADS
Model CB-832 is equipped with output connecting bars for attachment of the high current test leads
provided or any others suitable for the test application.
The following information on the selection of output leads will provide the user with a guide for
choosing the proper test leads for his application.
Due to the voltage drop from the inductive reactance of the test circuit, a significant loss of
current will result for each inch of test lead. Therefore, when choosing test leads, the length
and size of leads chosen will determine the maximum available test current. It is worthwhile
to sacrifice cross section of test leads for the sake of reducing length. Every inch of lead that
can be eliminated provides worthwhile increase in available test current. Heating is not a
significant problem in testing, even though the leads become hot. Paralleling of sufficient
cables provides higher test currents. Each cable can be fitted with a compression lug on each
end, then bolted to the output terminals or stab board of the test set and the breaker.
The two cables between the test set and the breaker should be twisted together or bundled
with tape or cord to maintain the close proximity, which minimizes inductive reactance.
OVERLOAD CAPACITY